Mystery 7s Slot

Progressive: No Jackpot: 6,000 Coins
Reels: 5 Paylines: 25
Coin Values: 0.01 up to 1 Bonus Game: Yes
Wild Symbol: Yes Multiplier: Yes
Scatter Symbol: Yes Free Spins: Yes
Released: July 2017 Software: iSoftBet

Mystery 7s Slot

Mystery 7s

Mystery 7s Slot

General Overview

Mystery 7s is an iSoftBet powered online slot with 25 fixed lines and 5 reels. Also known as Booster, it’s an excellent companion to the studio’s other neon-lit fruit machines like the 5-line Lucky 3 or Cherry Trio. The main draw in this game, however, is the intriguing bonus feature, which can produce long rallies of up to 100 free spins, multipliers as high as x5, and instant coin wins of up to 6,000 coins. So if it’s something simple and a little nostalgic that you’re after, then the Mystery 7 or Booster slot should be right up your alley, for a low to medium volatility. Find out more in the full review below.

Features and Bets

This intergalactic slot was launched on 27 June 2017, aiming at extended playing time with a high hit frequency of more than 50%. This makes it perfectly suitable for seasoned as well as recreational players.

As far as bets go, then you can set the coin value to be worth between 0.01 and 1 credits, for bets of 0.25 – 25 credits per spin.

Symbols and Bonuses

Mystery 7s features 7 types of regular but stacked symbols. From high to low, these are diamonds, red and blue 7’s, stars, triple, double and single BARs. All pay for 3 of a kind or better, except for the diamond, which also awards a nominal prize for just a couple of symbols on an active line. And the most you can win for any line is between 25 – 2,000 coins. Because of the spread, Mystery 7s is a medium to high variance machine.

Unfortunately, there are no wild cards in this retro game, but Bonus icons. These are active on all reels and don’t have a coin value in the base game like the rest. But what you do get for 3 or more (scattered) is a bonus game.

The feature comprises a board game type of a pre-round, where you can win up to 6,000 coins, up to 100 free spins, or free spins with a win multiplier of up to 5x. You only have one go as there won’t be any trade-ins or re-trigger opportunities during the freebies.

The free games bonus plays the same as the main game, with the only difference being the bonus icon which transforms into a paying Scatter. So for 3 or more of these during the feature, anywhere on the screen, you can also win x2 – x30 your total bet.


Mystery 7s, also known as Booster, is an iSoftBet powered online slot featuring classic fruit machine symbols in a modern space theme. Played at a low to medium volatility and high hit frequency, you can win up to 100 free spins, x5 win multipliers and 6,000 coins in an instant.

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Posted by CCJ Team

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